Pallet box

ABSTRACT

An improved pallet box having four sides hinged to a pallet base in a manner to permit the sides to pivot individually about respective axes near the upper surface of the base. The hinges for the sides allow the sides to be individually raised through a limited distance relative to the base to facilitate the movement of the sides one on top of each other to collapse the box for storage. In their vertical, erected positions, the sides are releasably interconnected and are locked against upward movement relative to the base. One side is pivoted near its upper margin to the pair of adjacent sides so that the one side can pivot in dump-truck fashion.

United States Patent 1 Bitney Mar. 25, 1975 PALLET BOX [76] Inventor: Robert H. Bitney, 10649 Morengo Dr., Cupertino, Calif. 95014 [22] Filed: May 10, 1973 [21] Appl. No.: 359,149

Related US. Application Data [62] Division of Ser. No. 157,517, June 28, 1971, Pat. No.

[52] US. Cl. 16/171, 403/327 [51] Int. Cl. E05d 1/06 [58] Field of Search 16/179, 115, 191, 199;

[56} References Cited UNITED STATES PATENTS 532,464 1/1895 Jackson 16/179 568,967 10/1896 Wilson 16/171 755,311 3/1904 Palmer 16/149 1,707,027 3/1929 Schwarzenberger 16/179 1,863,323 6/1932 Berne 16/149 X 1,920.975 8/1933 2,019,426 10/1935 Mabry 16/115 2,448,580 9/1948 Crosby 16/171 X 2,601,213 6/1952 Poupitch.. 85/1 H 2,656,216 10/1953 Bobroflun 16/179 3,104,477 9/1963 Edwill 403/106 X 3,331,108 7/1967 Fisher et al. 24/230 A 3,526,040 9/1970 Young 403/327 X Primary Examiner-James T. McCall Assistant E.\'aminer--Peter A. Aschenbrenner [57] ABSTRACT An improved pallet box having four sides hinged to a pallet base in a manner to permit the sides to pivot individually about respective axes near the upper surface of the base. The hinges for the sides allow the sides to be individually raised through a limited distance relative to the base to facilitate the movement of the sides one on top of each other to collapse the box for storage. In their vertical, erected positions, the sides are releasably interconnected and are locked against upward movement relative to the base. One side is pivoted near .its upper margin to the pair of adjacent sides so that the one side can pivot in dumptruck fashion.

1 Claim, 13 Drawing Figures PALLET BOX This is a division of application Ser. No. 157,517, filed June 28, 1971, now US. Pat. No. 3,747,794.

This invention relates to improvements in pallet boxes and, more particularly, to a pallet box having improved hinge means thereon.

Pallet boxes of conventional construction all have four sides which are hinged to a base in a manner to permit the sides to fold inwardly, one on top of each other in accordance with a predetermined sequence to thereby collapse the box for storage or transit. Piano hinges are generally used to mount the sides on the base and the heights of such hinges relative to the base are staggered to allow for the sequential stacking of the sides when the box is to be collapsed. This feature is not satisfactory because the means for mounting the hinges on the base at different levels do not usually have sufficient strength to permit the hinges to withstand rough handling. For this reason, conventional pallet boxes are oftentimes damaged to the extent that they are discarded rather than repaired.

The present invention provides a pallet box which improves upon conventional pallet boxes in that it uses an improved hinge which, when coupled to a respective side, allows limited vertical movement of the side relative to the the base of the pallet box to which the hinge is secured. In this way, the side can be more easily manipulated into and out of a stored position in which it is in a vertical stack with the other sides of the pallet box. To this end, the hinge has a relatively strong yoke which is held captive in and is vertically shiftable relative to a housing secured to the base of the box, the yoke being movable through a vertical distance, such as a distance equal to the maximum height of the uppermost side ofthe stack of collapsed sides. In this way, any one of the sides can form the top of the stack and the sides need not be stacked in any particular pattern or sequence.

The hinge of this invention also allows the sides to pivot outwardly as well as inwardly. When a side is pivoted outwardly, it forms a ramp extending outwardly and downwardly from the pallet base, thus permitting effective removal of certain kinds of materials or products carried in the box.

Still another aspect of the present invention resides in the fact that each hinge of the pallet box has a releasable Iock associated with it so that the corresponding side of the box, when it is in its vertical position, is releasably held against any vertical movement relative to the base. This feature, along with braces at the vertical margins of the sides, prevents collapse of the sides until the hinges are unlocked, thereby providing a safety feature which protects the contents of the box and prevents spilling of such contents from the box.

A further aspect of the pallet box of this invention is the provision of second hinge for pivotally mounting one side near its upper margin for movement relative to the adjacent two sides about a generallyhorizontal axis extending adjacent to and slightly below the top of the box. This allows the one side to pivot in dump-truck fashion and provide another way to empty the contents of the box. Thus, if the material if flowable, such as granular material or the like, it may be more advantageous to pivot the side about the axis near the top of the box than it would be to pivot it about the lowermost axis thereof. To provide for this capability, the lower hinge of the one side is constructed so that it can be quickly released from its attachment to the base. Thus, the lower margin of the one side can move outwardly and upwardly of the base.

The primary object of this invention is to provide an improved pallet box which can more easily be collapsed and stored than is capable with conventional pallet boxes by utilizing an improved hinge which is simple and rugged in construction and which permits vertical movement of each side relative to the base to which the sides are hingedly coupled so that the sides can be stacked in any sequence to avoid the need for sequential stacking as is now required with conventional pallet boxes.

Another object of this invention is to provide an improved pallet box of the type described wherein the hinge for each side of the box has lock structure associated with it to lock the corresponding side in its normal vertical position to prevent accidental collapse of the box and to prevent loss of the contents of the box.

A further object of this invention is to provide an improved pallet box of the aforesaid character wherein one of the sides of the box can pivot either about a generally horizontal axis near the base of the same or about a generally horizontal axis near the top of the box to render the pallet box more versatile for holding and permitting removal of materials of different types while maintaining a box of simple and rugged construction.

Another object of this invention is to provide an improved hinge for one side of a pallet box wherein the hinge can permit vertical movement of the side relative to the box or can be releasably locked to prevent such movement depending upon whether the side is to be collapsed or disposed in a vertical, operative position.

Other objects of this invention will become apparent as the following specification progresses, reference being had to the accompanying drawings for an illustration of several embodiments of the pallet box.

In the drawings:

FIG. 1 is a perspective view of the pallet box in its erected condition, showing several of the sides in dashed lines and in positions for permitting removal of the contents of the box;

FIG. 2 is a view similar to FIG. 1 but showing the box in a collapsed condition;

FIG. 3 is an enlarged, fragmentary, side elevational view of one side of the box, showing the side elevated relative to the base of the box;

FIG. 4 is a cross-sectional view taken along line 44 of FIG. 3;

FIG. 4a is an enlarged, fragmentary cross-sectional view of one of the hinges of the box;

FIG. 5 is a perspective view of another form of the hinge of this invention;

FIG. 6 is a view similar to FIG. 3 but showing a quickrelease means for the removable cover of the hinge of another side of the box;

FIG. 7 is a cross-sectional view taken along line 77 of FIG. 6, showing the releasable lock structure of the hinge;

FIG. 8 is a view similar to FIG. 7 but showing the way the cover plate is removed from the base;

FIG. 9 is a cross-sectional view taken along line 9-9 of FIG. 6;

FIG. 10 is an enlarged, cross-sectional view of a sec- 10-10 of FIG. 1;

FIG. 11 is a perspective view of another embodiment of the pallet box; and

FIG. 12 is a side elevational view of a part of the second hinge.

Pallet box 10 of this invention is shown in its erected state in FIG. 1 and in its collapsed state in FIG. 2. Box l includes a base 12 and four, imperforate, flat sides 14, 16, 18 and 20. The sides are hingedly connected to the base by improved hinge means hereinafter described so that the sides can pivot relative to the base about generally horizontal axes extending along and adjacent to the respective bottom margins of the sides. Moreover, such hinge means allows the sides to pivot at least through 180; thus, each side is capable of being pivoted inwardly or outwardly, as desired.

Base 12 is comprised of a flat, plate-like platform 22 to the underside of which is secured three spaced, elongated support members 24, 25 and 27 to maintain platform 22 elevated with respectto a supporting floor therebeneath. The two spaces formed below platform 22 by members 24, 25 and 27 are adapted to receive the forks of a forklift truck, whereby box can be lifted from a floor and carried by the truck to a desired location. Also, members 24 and 27 may be provided with recesses 29 (FIG. 1) therein to receive such forks.

Base 12 and sides 14-20 can be of any suitable construction. For purposes of illustration only, they are formed of wood, the sides and platform 22 being of a suitable plywood material and members 24 being beams on end, cut to length, and nailed or otherwise secured to the platform.

The improved hinge means of this invention is used to pivotally interconnect each of sides 14-20 to base 12. Such hinge means includes a hinge for each of the sides, respectively, the four hinges being basically the same, the only difference being the way in which the hinges are secured to the base. Hinge 26, coupled to side 14, is secured to the outer face of support member 24; a pair of hinges 28, coupled to sides 16 and 20, respectively, are secured to the ends of the central support member and a hinge 30 (FIGS. 6-9), secured to side 18, is releasably coupled to the outer face of support member 27.

Hinge 26, shown in FIGS. 3 and 4, includes a transversely U-shaped connecting member 32 having a pair of opposed sides 34 and a bight 36 interconnecting sides 34. The length of sides 34 is less than the width of side 14 as shown in FIG. 1 and a part of the lower margin of side 14 is received between sides 34, as shown in FIG. 4. A pair of fasteners 38 secure side 14 to sides 34.

The central part of the bottom margin of side 14 is provided with a notch 40 which receives a transversely circular bar 42, bar 42 also being between sides 34 and directly above bight 36. Member 32, and thereby side 14, is rotatably mounted on bar 42, the latter having a yoke 44 secured thereto and extending downwardly therefrom through a central transversely U-shaped opening 45 in bight 36 (FIG. 3) for attachment to support member 24. Yoke 44 includes a pair of rigid, parallel, generally vertical members 46 secured at their upper ends to bar 42. A crosspiece 47 interconnects the lower ends of members 46.

Bar 42 may be tubular as shown in FIG. 5 to receive the lower portion ofa frame, such as an open frame for holding a fabric or canvas side. Such a frame can be used to form part of a mail bag or the like.

Members 46 and crosspiece 47 are shiftably mounted within an open top, hollow housing 48 having an outer wall 50, an inner wall 52 (FIG. 4), and a pair of opposed sidewalls 53 spanning the distance between walls and 52. The transverse dimension of member 46 is substantially the same as the width of sidewalls 53, i.e., the spacing between walls 50 and 52; whereas, the transverse dimension of crosspiece 47 is less than that of member 46 as shown in FIG. 4 to permit yoke 44 to move up'and down with respect to a spring-loaded lock plate 54 pivotally mounted by a pin 56 to a bearing 57 secured to the upper portion of inner wall 52 within housing 48. A leaf spring (FIG. 4a) biases plate 54 into its locked position overlying crosspiece 47 when yoke 44 is in its lowermost position. Thus, the yoke is locked against upward movement.

When lock plate 54 is forced toward inner wall 52, it clears crosspiece 47, allowing yoke 44 to be elevated until crosspiece 47 abuts bearing 57, the latter then serving as a stop. The hinge is unlocked by inserting a tool through an opening 60 in outer wall 50 and into forcible engagement with lock plate 54 to cause the latter to move toward inner wall 52 against the bias force of spring 55 and out of overlying relationship to crosspiece 47.

Housing 48 has a pair of side flanges 62 secured by fasteners 66 to the outer face 68 of support member 24. Outer wall 50 may or may not be removable. If it is removable, it can be secured by screws or the like to bearing 57 and to another part of housing 48.

Side 14 has a pair of L-shaped channel members 70 and 72 secured by fasteners 74 to its outer surface near the opposed side margins thereof as shown in FIG. 1. Members 70 and 72 have flanges 75 which extend along the outer surfaces of sides 16 and 20, respectively, to brace the latter and hold the same against outward movement when sides 14, 16 and 20 are in their vertical, operative positions on platform 22 (FIG. 1). One or more aircraft fasteners 77 of the flat-head type releasably connect flanges 75 to sides 16 and 20 to prevent outward pivotal movement of side 14 relative to base 12 when the sides 14, 16 and 20 are in their operative, vertical positions. When side 14 is pivoted outwardly and downwardly into the dashed line position of FIG. 1, it provides a ramp for permitting removal of the contents of the box from only one side thereof as the other sides remain vertically disposed.

Each ofthe pair of hinges 28 is substantially identical with hinge 26 except for the means for mounting each hinge 28 on base 12, such means including a housing 480 provided with a pair of generally parallel side flanges 620 (FIG. 1) secured by fasteners 66a to the opposed sides of central support member 25, whereby housing 48a is rigidly secured to the corresponding end of support member 25. While hinge 28 of side 16 is not shown in FIGS. 1 and 2, it is to be understood that this hinge is also secured to the opposide end of support member 25 in the same manner as is shown in FIG. 2 with respect to hinge 28 of side 20.

Housing 48a has a vertically shiftable yoke and a spring loaded pivotal lock plate mounted therein, the yoke and lock platebeing substantially identical to that of hinge 26. The yoke is coupled to a U-shaped connecting member rigid to the lower margin of the corresponding side of the pallet box. Thus, each of sides 16 and 20 can be elevated to the same extent as side 14.

Hinge 30,-shown in FIGS. 69, is essentially the same in construction as hinge 26 except that it can be separated from support member 27. To this end, hinge 30 has an upper, transversely U-shaped member 32b to which a bar 42b is rotatably coupled, the bar being connected to the upper end of a yoke 44b shown in dashed lines in FIG. 6, and a lock plate 54b (FIG. 7). whose lower margin 58b normally overlies crosspiece 47b when yoke 44b is in its lowermost position. Yoke 44b is slidable vertically within a housing 48b which is removably coupled to a connector plate 49b, the latter having a transversely, U-shaped central body 51b (FIG. 9) and a pair of side flanges 53b for attachment by fasteners 66b to the outer side face 55b of support member 27. Housing 48b has a lock element 57b rotatably mounted on the'inner wall 52b thereof, element 57b having a key hole or recess 59 b therein for receiving a suitable tool, whereby element 57b can be rotated with respect to inner wall 52b. For purposes of illustration only, hole 59b is square to receive a transversely square tool.

Lock element 57b has a pair ofdiametrically opposed projections or ears 61b (FIG. 6) which are adapted to pass through corresponding recesses 63b in the body 51b of member 49b when housing 48b is moved into the position shown in FIG. 7, following which element 57b can be rotated so that cars 61b are out of alignment with recesses 63b and engage the outer face of body 51b. A recess 65b (FIG. 9) is formed in support member 27 to accommodate the innermost portions of element 57b and allow the latter to rotate relative to support member 27. When ears 61b are in the positions shown in FIG. 6, housing 48b islocked to connector plate 49b. However, when ears 61b are moved back into alignment with recesses 63b, housing 48b can be separated from connector plate 4%.

Housing 48b has a first, lower opening 60b (FIG. 7) through which a tool can extend to move lock plate 54b to the right when viewing FIG. 7 to permit upward movement of yoke 44b. Housing 48b is provided with a second, upper opening 65b through which a tool can pass as it moves toward and into coupled relationship with element 57b for rotating the latter. An opening 67b in lock plate 54b also permits the passage of the tool thereth rough. FIG. 8 shows the way in which housing 48b can be moved away. from member 49b when ears 61b are in alignment with recesses 63b.

Pallet box has a pair of additional hinges 80 and 82 shown on the box in FIG. 1 for pivotally interconnecting the upper margin of side 18 to the adjacent upper corners of sides 16 and 20, respectively. Hinges 80 and 82 have a common hinge axis which is generally horizontal so that side 18 can pivot about such edge axis when housing 48b is released from member 49b as described above. FIG. 1 shows side 18 pivoted upwardly in dumptruck fashion. This feature provides another way in which the contents'of the pallet box can be removed therefrom while three of the four sides remain vertically disposed. Certain materials carried by the box, such as granular or particulate materials, can sometimes be more easily removed from the box when side 18 swings upwardly and outwardly rather than downwardly and outwardly.

Each of the two hinges 80 and 82 are substantially the same in construction except that one is a right-hand hinge and the other is a left-hand hinge. For purposes of illustration, reference will be made to hinge 82 as rounded by an annular, outer peripheral flange 88 integral with body 90. Side (FIG. 10) is countersunk to accommodate body 90 and flange 88 is secured in any suitable manner by fasteners to side 20. Body 90 has a central opening 92 therethrough, and a conventional rotatable aircraft fastener 96 extends through opening 92 and is carried by side 20. Fastener 96 has a flat head 93 which can be rotated from within by a screwdriver or the like. Part 86 has a bar 94 secured thereto across a central opening 95 therein, bar 94 defining the anchoring pin for fastener 96. Bar 94 can be defined by the central part of an S-shaped spring member 97 (FIG. 11) whose outer, curved ends functionally engage the curved,.inner surface of dish-shaped body 108 of part 86.

Part 86 has a first, L-shaped section 98 secured by fasteners 100 to the outer face of side 18 and a second section 106'coupled by a hinge pin 102 to the adjacent side flange 104 of section 98. Section 106 has dishshaped portion 108 as a part thereof, portion 108 being complemental to and receivable in body 90 of part 84. Fastener 96 is adapted to be releasably coupled to bar 94 upon being rotated through a certain angle, such as 90, to thereby interconnect parts 84 and 86 when portion 108 is complementally received within body 90. Thus, sides 18 and 20 can be interconnected.

Hinge pin 102 allows part 86 to rotate in a counterclockwise sense when viewing FIG. 10 into a position in which portion 108 is received within a recess 110 on the inner face of side 18. This permits part 86 to present a minimum projection from the inner face of side 18 to thereby facilitate vertical stacking of side 18 on side 14 as shown in FIG. 2. When the aircraft fasteners of hinges 80 and 82 are connected to respective bars 94, sides 16 and 20 are releasably locked to side 18 and are thereby releasably held in their vertical positions. This prevents pivoting movement of sides 16 and 20 and also prevents pivoting movement of sides 14 and 18.

OPERATION Pallet box 10 is assembled by connecting sides 14-20 to base 12 with the use of hinges 26, 28 and 30 and the parts of hinges 80 and 82 are secured to respective sides 16, 18 and 20. Assuming the sides are in their operative, vertical positions shown in FIG. 1, the pallet box is ready to receive and contain articles or materials therein for shipment or storage. In such positions, the sides will engage and extend upwardly from platform 22 and will engage each other sufficiently to effectively close the interior of the box except for the open top. A suitable top cover can be provided, if desired. Also, when the sides are in their operative positions, hinges 26, 28 and 30 are locked against upward movement by virtue of the positions of their lock plates. Also, the upper margins of sides l6, l8 and 20 are releasably interconnected by fasteners 96 of hinges 80 and 82.

The assembled pallet box 10 can be moved, empty or full, with a forklift truck from place to place when the forks of the forklift are received within the spaces between support members 24, 25 and 27. The contents of the pallet box can be removed in any of the following ways: the box can be turned over onto one of its sides; side 14 can be pivoted downwardly and outwardly to form a ramp as described above; or side 18 can pivot upwardly and outwardly in dump-truck fashion. The nature of the contents will generally determine how they will be removed from the box.

When it is desired to collapse the box, such as after use and before storage of the box, hinges 80 and 82 are disassembled by manipulating fasteners 96 to permit separation of parts 84 from respective parts 86 of the hinges. When this occurs, sides 16 and 20 are released from their connection with side 18 and side 16 is first pivoted inwardly and onto the upper surface of platform 22. Side 16 need not be initially elevated before being pivoted inwardly. Then, side 20 is elevated slightly and then pivoted inwardly and onto side 16. Next, side 14 is elevated still further and then pivoted inwardly onto side 20. Finally, parts 86 of hinges 80 and 82 are pivoted inwardly so that portions 108 are received with recesses 110, whereupon side 18 is elevated sufficiently so as to permit it to pivot onto side 14 as shown in FIG. 2. The box is then completely collapsed and can be stacked on another, collapsed or assembled pallet box 10. To move the sides into their operative, vertical positions, the last-mentioned sequence is reversed, starting with side 18, then side 14, then sides 20 and 16.

While sides 14-20 have been described as being imperforate and made of wood, it is possible that they could be of other materials and configurations. For instance, the sides could be expanded metal or of canvas material, such as to form a mail bag or the like. In any case, hinges 26, 28 and 30 would still be used to interconnect the base and the sides. Also, the number and dimensions ofthe sides can differ from those described above.

Another embodiment of a hinge is shown in FIG. and includes a yoke 122 provided with a pair of spaced cables or cords 124 coupled by a connector 126 to the outer surface of a cylindrical, hollow, member 128 rotatably mounted on a pair of stub shafts 130. Member 128 is hollow and has a window-shade structure (not shown) therewithin including a spring which biases member 128 in a clockwise sense relative to shafts 130 when viewing FIG. 5.

A bar 132 is attached to yoke 122 and is coupled to a U-shaped connecting member 134 which is to be attached to the side of a corresponding pallet box. Stub shafts 130 are adapted to be secured in some suitable manner to the base of the pallet box.

In use, the hinge of FIG. 5 operates in substantially the same manner as hinge 26 except that when the side coupled with member 134 is vertically disposed, the window-shade structure in member 128 forceably pulls yoke 122 downwardly until member 134 engages the upper surface of the base of the pallet box. Thus, the window-shade structure and cables 124 provide another way in which a side of the pallet box is coupled to the base thereof.

Another embodiment of the pallet box of this invention, denoted by the numeral 150, is shown in FIG. 11 and has a base 152 substantially the same in construction as base 12 of FIGS. 1 and 2, Box 150 has four sides 154, 156, 158 and 160 which are hingedly secured to base 152 by hinges of the type described above with respect to body 10. Sides 154 and 158 are each provided with a hinge 162 constructed substantially the same as hinge 26 of FIG. 1. Sides 156 and 160 are each secured by a hinge 164 to base 152, hinge 164 being substantially the same as hinge 28 of FIG. 1 except that hinge 164 has a housing 166 which is releasably locked to a U-shaped body 168 in the manner described above with respect to hinge 30 and as shown in FIGS. 6-9.

One side margin of side 156 is coupled by a pair of vertically spaced hinges 170 to the adjacent side margin of side 154. Similarly, a pair of vertically spaced hinges 172 couple theopposite side margin of side 156 to the adjacent side margin of side 158. A pair of vertically spaces hinges 174 connect one side margin of side 160 with the adjacent side margin of side 154, and a pair of vertically spaced hinges 176 (only one of which is shown in FIG. 11) couple the opposite side margin of side 160 to the adjacent side margin of side 158.

Each of the hinges 170, 172, 174 and 176 is substantially the same in construction as each of the hinges and 82 (FIG. 1), in that each such hinge is provided with a pair of separable parts with each part having a dish-shaped body of the type shown in FIG. 10 and quick release fastener means for interconnecting the dish-shaped body when one is complementally received within the other. Also, one of the parts has a pair of hingedly interconnected sections so that one of the sections can pivot into a retracted position when the sides are separated from each other.

Hinges 170, 172, 174 and 176 connect the sides together when the same are in their vertical, operative positions. When the parts of each of the last-mentioned hinges are separated from each other, by manipulating the quick release fastener means thereof, the sides can be moved into the vertical stacked positions of the type shown in FIG. 2 for storage or transit. The sides of box can move through a limited distance relative to base 152 to facilitate the stacking of the sides. Also, hinges 162 and 164 permit the respective sides to pivot through an angle of at least 180 relative to the base.

The upper hinges 170 and 172 permit side 156 to pivot outwardly and upwardly since the dish-shaped portions of these two hinges are rotatable relative to base 152 and hinge 164 of side 156 is separable from base 152. The hinge line of hinge 170 is coextensive with that of binge 172.

Similarly, side can pivot in dump-truck fashion about a hinge line extending through the dish-shaped portions of the upper hinges 174 and 176. The lower hinges 170, 172, 174 and 176 are used merely to interconnect adjacent sides. The upper hinges are sufficiently close to the open top of box 150 to permit unrestricted rotational movement of sides 156 and 160 relative to sides 154 and 158.

A top cover (not shown) may be pivotally attached to one of the sides of the pallet box of this invention for movement into and out of closing relationship to the open top of the box. A suitable hinge may be provided to pivotally connect the cover to move into a collapsed condition along with the sides of the box.

I claim:

1. A self-locking, extensible hinge for a pallet box having a base and a number of sides comprising: a yoke having a bar secured to one end thereof; an elongated, transversely U-shaped connecting member having a bight and a transversely U-shaped opening through the bight, said connecting member adapted to be coupled to the lower margin of one of said sides, said bar being ro tatably received within said connecting member and supported at its ends on said bight, said yoke including a pair of spaced rigid members extending through the opening in the bight; said bar being secured to said rigid members at one end of the yoke, and a crosspiece secured to said members at the opposite end of the yoke, a hollow housing adapted to be secured to the base ineluding an aperture through which the members extend so that the crosspiece is disposed interiorly of the housing, a plate shiftably mounted within the housing, movable into and out of an interlocking relationship with the crosspiece, means biasing the plate into said interlocking relationship normally prevent movement of the crosspiece with respect to the housing when the crosspiece is at a location remote from said aperture, said housing having a tool-receiving opening aligned with the plate to move the latter out of said relationship and to thereby permit movement of the crosspiece to a position proximate the aperture, and means preventing a complete withdrawal of the crosspiece from the housing. 

1. A self-locking, extensible hinge for a pallet box having a base and a number of sides comprising: a yoke having a bar secured to one end thereof; an elongated, transversely U-shaped connecting member having a bight and a transversely U-shaped opening through the bight, said connecting member adapted to be coupled to the lower margin of one of said sides, said bar being rotatably received within said connecting member and supported at its ends on said bight, said yoke including a pair of spaced rigid members extending through the opening in the bight; said bar being secured to said rigid members at one end of the yoke, and a crosspiece secured to said members at the opposite end of the yoke, a hollow housing adapted to be secured to the base including an aperture through which the members extend so that the crosspiece is disposed interiorly of the housing, a plate shiftably mounted within the housing, movable into and out of an interlocking relationship with the crosspiece, means biasing the plate into said interlocking relationship normally prevent movement of the crosspiece with respect to the housing when the crosspiece is at a location remote from said aperture, said housing having a tool-receiving opening aligned with the plate to move the latter out of said relationship and to thereby permit movement of the crosspiece to a position proximate the aperture, and means preventing a complete withdrawal of the crosspiece from the housing. 